WIKIMEDIA, MATTOSAURUSA brief, low-dose of penicillin can impact the gut microbiomes of young mice and lead to obesity later in life, New York University’s Martin Blaser and his colleagues showed in Cell this week (August 14). The researchers suggested that the microbial changes may influence the development of metabolic pathways down the line.

The results of this mouse study “bring a different level of proof” to the link between antibiotics and long-term health, said microbiologist Federico Rey of the University of Wisconsin-Madison who was not involved with the work.

“When babies develop, there are other critical developmental windows,” Blaser told The Scientist. “Even though the effects we saw on microbes were transient, the [weight gain] was permanent, suggesting that there is a developmental window—a time when microbes are influencing the development of metabolism.”

VIRGINIA TECH COLLEGE OF AGRICULTURE AND LIFE SCIENCESA parasitic plant (Cuscuta pentagona) swaps messenger RNA (mRNA) with two of its hosts, tomato and Arabidopsis thaliana, Virginia Tech’s Jim Westwood and his colleagues reported in Science this week (August 14). It’s not yet known how, if at all, those shuttling mRNAs function in each species.

“The high volume of transcripts being exchanged is surprising,” Consuelo De Moraes, a plant biologist and ecologist at the Swiss Federal Institute of Technology in Zurich who was not involved in the work, told The Scientist in an e-mail. “The movement and functions of mobile RNAs in plants is a relatively new and exciting topic… This paper extends the frontiers of possibilities to plant-plant interactions.”

CDC PUBLIC HEALTH IMAGE LIBRARYThe transmission of chikungunya virus is mediated by a three-way interaction involving the viral strain, mosquito vector genotype, and ambient temperature, a team led by the Pasteur Institute’s Karima Zouache reported this week (August 13) in Proceedings of the Royal Society B.

“There are other factors that can affect vector competence, but environmental temperature will likely have a strong impact on mosquitoes because, like other insects, mosquitoes are ectotherms,” said entomologist Courtney Murdock at Pennsylvania State University who was not involved in the work. “Thus, temperature variation will have a large influence on mosquito physiology, development rates, longevity, and reproduction, all of which shape a mosquito’s ability to transmit disease.”

FLICKR, TAMAKI SONOResearchers at the Washington University School of Medicine in St. Louis analyzed more than 900 fecal samples collected from 58 premature babies to investigate how the infant gut microbiome develops. The results of their analysis were published in PNAS this week (August 11).

“I think the paper does a nice job of showing that premature babies develop differently from full-term babies . . . it is not just a function of colonization after birth,” Rob Knight from the University of Colorado, Boulder, told The Scientist in an e-mail. “Differences in gut physiology or in the infant immune system could explain this pattern.”

Lab-Grown 3-D Brain Tissue Mimics Cortex
From cortical neurons, researchers have engineered rat tissue that formed complex networks of functioning neurons and appeared to behave normally after an injury.